Coated ice melting compositions

ABSTRACT

Ice melting compositions, methods for manufacturing ice melting compositions, and methods for melting ice are disclosed. The ice melting compositions can include a coarse deicing particle nucleus and a fine deicing particle coating substantially surrounding the coarse deicing particle nucleus. The fine particle coating can be attached or bonded to the coarse particle nucleus with a binder. The coarse particle nucleus and the fine particle coating can have a variety of particle sizes.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a divisional application of U.S. PatentApplication Publication No. 2015-0014576, filed Jul. 10, 2013, thecontents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present disclosure generally relates to ice melting compositions.More particularly, the disclosure relates to ice melting compositionshaving improved coatings and ice melting capabilities.

Snow and ice can create hazardous conditions on sidewalks and roads. Todeal with such hazardous conditions, it is known to spread salt on thesnow or ice. As the salt particles come into contact with the snow orice, melting begins and water is produced. This water and salt mixtureis called “brine.” Brine freezes at lower temperatures than regularwater, so it remains a liquid at temperatures below freezing. The brineand salt particles work their way further into the snow and ice andeventually down to the road or sidewalk surface. From here, brine canspread out under the ice, breaking the bond between the road or sidewalksurface and the ice. The remaining snow and ice floats on top of theliquid brine, allowing traffic to easily break it down into slush.Finally, snow plows can move the slush to the side of the road orsidewalk.

BRIEF SUMMARY OF THE INVENTION

Surprisingly, the present inventors developed an ice melting compositionthat provides improved ice melting characteristics. In one aspect, theice melting composition includes a coarse deicing particle nucleus, afine deicing particle coating substantially surrounding the coarsedeicing particle nucleus and being bonded to the coarse deicing particlenucleus with a binder. The binder is a sodium chloride brine with yellowprussiate of soda.

In another aspect, the ice melting composition includes a coarse deicingparticle nucleus having a particle size range from about 500 μm to about10,000 μm, a fine deicing particle coating substantially surrounding thecoarse deicing particle nucleus and being bonded to the coarse deicingparticle nucleus with a binder. The fine deicing particle coatingconsists of fine deicing sodium chloride particles having a particlesize range from about 20 μm to about 600 μm.

The foregoing has outlined rather broadly the features and technicaladvantages of the present disclosure in order that the detaileddescription that follows may be better understood. Additional featuresand advantages will be described. It should be appreciated by thoseskilled in the art that the conception and the specific embodimentsdisclosed may be readily utilized as a basis for modifying or designingother embodiments for carrying out the same purposes of the presentdisclosure. It should also be realized by those skilled in the art thatsuch equivalent embodiments do not depart from the spirit and scope ofthe disclosure as set forth in the appended claims.

The reference to particle size range in the present specification refersto an average particle size. Thus, reference to a particle size range ofabout 1,000 μm refers to particles having an average particle size ofabout 1,000 μm.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 shows the ice melting capabilities of ice melting compositionshaving different particle sizes.

FIG. 2 shows the ice melting capabilities of certain aspects of thepresently disclosed ice melting compositions.

FIG. 3 shows the ice melting capabilities of other aspects of thepresently disclosed ice melting compositions.

DETAILED DESCRIPTION OF THE INVENTION

In certain aspects, the ice melting compositions comprise a coarsedeicing particle nucleus. The coarse deicing particle nucleus is coatedwith a fine deicing particle coating. The fine deicing particle coatingsubstantially or fully surrounds the coarse deicing particle nucleus andis bonded or attached to the coarse deicing particle nucleus with abinder.

In accordance with certain aspects, the coarse deicing particle nucleuscomprises a coarse sodium chloride particle. Other illustrative,non-limiting examples of coarse particles that can be used in accordancewith the present disclosure are selected from calcium chloride, sodiumacetate, magnesium chloride, potassium acetate, potassium formate,calcium magnesium acetate, calcium acetate, magnesium acetate, potassiumchloride, sodium formate, urea, and any combination thereof. The nucleuscan comprise one or more of the foregoing compounds and/or anycombination of the foregoing compounds. In other aspects, the nucleuscan comprise a coarse particle of sodium chloride with one or more ofcalcium chloride, sodium acetate, magnesium chloride, potassium acetate,potassium formate, calcium magnesium acetate, calcium acetate, magnesiumacetate, potassium chloride, sodium formate, or urea. The nucleus cancomprise one or more of the foregoing compounds and/or any combinationof the foregoing compounds.

In certain aspects, the nucleus comprises a coarse particle compound,such as sodium chloride, having a particle size range from about 500 μmto about 10,000 μm. In other aspects, the nucleus comprises a coarseparticle compound having a particle size range from about 1,000 μm toabout 8,000 μm. In further aspects, the nucleus comprises a coarseparticle compound having a particle size range from about 1,000 μm toabout 5,000 μm. Additionally, the nucleus may comprise a coarse particlecompound having a particle size range from about 1,000 μm to about 4,000μm, from about 2,000 μm to about 4,000 μm, from about 500 μm to about3,500 μm, from about 2,000 μm to about 6,000 μm, from about 4,000 μm toabout 9,000 μm, from about 2,300 μm to about 3,400 μm, or any othersub-range of about 500 μm to about 10,000 μm. Thus, in one aspect, theice melting composition can comprise a nucleus of coarse deicingparticle sodium chloride having a particle size range from about 2,300μm to about 3,400 μm.

As previously mentioned, the coarse deicing particle nucleus of the icemelting composition is coated with a fine deicing particle coating. Incertain aspects, the fine particle coating comprises sodium chloride. Inother aspects, the fine particle coating consists of sodium chloride. Inthe aspect where the fine particle coating consists of sodium chloride,no compounds or salts other than sodium chloride are included in thefine particle coating. For example, a salt, such as calcium chloride,would be excluded from the coating when the coating consists of sodiumchloride. In other aspects, the fine particle coating may contain othercompounds and/or salts known in the art of ice melting, such as calciumchloride or a combination of calcium chloride and sodium chloride. Instill further aspects, the ice melting composition excludes calciumchloride. Additionally, in some aspects, the fine deicing particlecoating excludes calcium chloride. While it has been suggested in theart that calcium chloride can provide beneficial effects in ice meltingcompositions, the present inventors have discovered that beneficialeffects can be obtained with an ice melting composition that excludescalcium chloride or excludes calcium chloride from its fine deicingparticle coating.

The fine particle coating comprises particles having a particle sizerange from about 20 μm to about 600 μm. In certain aspects, the fineparticle coating comprises particles having a particle size range fromabout 50 μm to about 500 μm. In other aspects, the fine particle coatingcomprises particles having a particle size range from about 100 μm toabout 400 μm, from about 100 μm to about 200 μm, from about 20 μm toabout 150 μm, from about 200 μm to about 500 μm, from about 100 μm toabout 125 μm, or any other sub-range of about 20 μm to about 600 μm.Thus, in one aspect, the ice melting composition can comprise a finedeicing particle sodium chloride coating having a sodium chlorideparticle size range from about 100 μm to about 125 μm. In anotheraspect, the ice melting composition can comprise a fine deicing particlecoating, wherein the coating consists of sodium chloride particles,further wherein the sodium chloride particles have a particle size rangefrom about 100 μm to about 125 μm.

It is advantageous if the particles forming the fine particle coatinghave a particle size range that is smaller than the particle size rangeof the coarse particle nucleus. In this regard, however, it is believedthat some overlap (e.g. about 20% or less) is tolerable.

The binder used to bind or attach the fine particle coating to thecoarse particle nucleus can include binders known in the art or it cancomprise certain binders described below that have been found to yieldbeneficial technical effects. In certain aspects, the binder can be aliquid. The binder may comprise additional components, such as one ormore dyes and/or one or more corrosion inhibitors. The dyes, forexample, can impart color to the deicing particle and the corrosioninhibitors can reduce or inhibit the corrosion of a metal surface thatmight come into contact with the deicing particle.

The selection of the binder can be based on a number of factors. Forexample, in certain aspects, the binder may be selected based upon itscontribution to the ice melting process. Also, if the binder is a brine,it could be saturated at room temperature. For example, a saturatedmagnesium chloride brine can be used in accordance with the presentdisclosure, as can a saturated sodium chloride brine with YPS. Inaccordance with the present disclosure, the term “YPS” refers to yellowprussiate of soda in the anhydrous form. Further, in certain aspects,the binder may not freeze at low temperatures, preferably as low as −5°F. If a brine of a common salt such as sodium chloride is employed,obtaining a saturated solution that does not freeze is difficult. Forexample, the use of a sodium chloride brine to wet a coarse particlenucleus can result in a reduction of ice melting efficiency, which canbe attributed to freezing of the brine. In still further aspects, thepresently disclosed binder could be chosen so that the presentlydisclosed fines (fine particle coating) adhere thereto but do notdissolve therein. Finally, the binder could be capable of wetting theentire outer surface, or substantially the entire outer surface, of thecoarse deicing particle nucleus.

To overcome problems associated with certain prior art binders, thebinder may be selected from the group consisting of magnesium chloridebrine and sodium chloride brine with YPS. In other aspects, the bindercan be saturated magnesium chloride brine or saturated sodium chloridebrine with YPS. Other illustrative, non-limiting examples of bindersthat can be used in accordance with the present disclosure are solutionsof inorganic salts, solutions of organic compounds, solutions of organicsalts, organic liquids, inorganic salt solutions containing bio-derivedorganic materials such as sugars and carbohydrates, and organic solventssuch as glycerol, propylene glycol, 1,3 propanediol, or any combinationthereof. In a particular aspect, the binder is a sodium chloride brinewith YPS.

A saturated magnesium chloride brine solution has a concentration ofapproximately 35% magnesium chloride at 20° C. As an illustrative,non-limiting example, a saturated magnesium chloride brine solution canbe prepared by adding about 160 g of magnesium chloride hexahydrate toabout 40 cm³ of water. The mixture can be warmed while stirring untilall of the magnesium chloride has dissolved. Subsequently, the mixtureis allowed to cool and any solid precipitate can be removed byfiltration. Of course, the amount of magnesium chloride needed to createthe brine depends upon the volume of water being used and thisdisclosure is intended to cover any amounts of the components that wouldyield a saturated magnesium chloride brine solution having aconcentration of approximately 35% magnesium chloride at 20° C.

As previously noted, in certain aspects, the binder is a saturatedsodium chloride brine with YPS. As a saturated solution of sodiumchloride (about 26.4 wt. %) is cooled below 32° F., sodium chloridedihydrate will begin to form and crystallize. The crystallization ofsodium chloride dihydrate leads to freezing of the salt. However, if YPSis added to the saturated sodium chloride brine solution, the solubilityof the salt is inhibited so that a saturated solution could be preparedat a lower sodium chloride concentration and thus have a lower freezingpoint (the temperature at which sodium chloride dihydrate crystallizesfrom solution). Also, as the amount of YPS added to the brine increases,the amount of sodium chloride dissolved to reach saturation decreasesand the precipitation of sodium chloride dihydrate should be prevented.

In accordance with certain aspects of the present disclosure, asaturated sodium chloride brine with YPS can be formed by dissolvingfrom about 0.2 g to about 1.4 g of YPS in about 200 mL water and addingan excess of sodium chloride (about 80 g). Of course, the amount ofsodium chloride to be added depends upon the volume of the water beingused. The binder can be formed from any volume of water and any amountof sodium chloride can be added to the water, so long as the amount issufficient to form a saturated sodium chloride solution (about 24% byweight). The amount of YPS to be added is dependent upon the amount ofsodium chloride added. In certain aspects, the saturated sodium chloridebrine solution comprises about 700 ppm to about 5,000 ppm YPS. Inadditional aspects, the saturated sodium chloride brine solutioncomprises about 3,500 ppm to about 4,500 ppm YPS and in other aspects,the saturated sodium chloride brine solution comprises about 4,300 ppmto about 4,400 ppm YPS. If the total volume of the sodium chloridebinder was about 200 mL, then 1.1 g of YPS would equal about 4,500 ppm.Once all components have been added to the water, the resulting solutioncan be stirred or shaken and any solid precipitate can be removed byfiltration or settling.

The presently disclosed ice melting compositions can comprise variousamounts of each of the coarse deicing particle nucleus, the fine deicingparticle coating, and the binder. For example, in one aspect, the icemelting composition comprises from about 60% to about 97% of the coarseparticle nucleus, from about 0.5% to about 6% of the binder, and fromabout 3% to about 35% of the fine particle coating. In another aspect,the ice melting composition comprises from about 84% to about 90% of thecoarse particle nucleus, from about 2% to about 4% of the binder, andfrom about 8% to about 12% of the fine particle coating. As previouslymentioned, in any of these aspects, the coarse particle nucleus cancomprise sodium chloride, the binder can comprise a magnesium chloridebrine or a sodium chloride brine with YPS, and the fine particle coatingcan comprise or consist of sodium chloride.

In one particular aspect, the ice melting composition comprises about87% by weight of a coarse particle sodium chloride nucleus, about 10% byweight of a fine particle coating, and about 3% by weight of a saturatedmagnesium chloride brine binder. In this aspect, the fine particlecoating can comprise sodium chloride or, it can consist of sodiumchloride. The particle sizes of the sodium chloride nucleus can rangefrom about 2,300 μm to about 3,400 μm and the particle sizes of the fineparticle coating can range from about 100 μm to about 125 μm.

In another particular aspect, the ice melting composition comprisesabout 87% by weight of a coarse particle sodium chloride nucleus, about10% by weight of a fine particle coating, and about 3% by weight of asaturated sodium chloride brine binder with YPS. The saturated sodiumchloride brine binder includes from about 4,300 ppm to about 4,400 ppmYPS. In this aspect, the fine particle coating can comprise sodiumchloride or, it can consist of sodium chloride. The particle sizes ofthe sodium chloride nucleus can range from about 2,300 μm to about 3,400μm and the particle sizes of the fine particle coating can range fromabout 100 μm to about 125 μm.

The following describes a method of making the presently disclosed icemelting compositions. In general, an appropriate amount of the coarsedeicing particle nucleus is added to a mixer. Subsequently, a binder isadded to the mixer to wet the outer surface of the coarse deicingparticle nucleus. Thereafter, fine deicing particles are added to themixer, in a manner to substantially bind or adhere the fine deicingparticles to the surface of the coarse particle nucleus. Alternatively,the fine particles forming the fine particle coating can be added to themixer after addition of the coarse particle nucleus and subsequently,the binder can be added. After addition of the binder, the contents ofthe mixer are mixed to thoroughly wet the outer surface of each nucleusparticle. Also, after the addition of the fine particle coating, thecontents of the mixer can be mixed to be sure that the entire outersurface of each nucleus particle, or a substantial portion thereof, isthoroughly coated with the fine particles. The coating process may alsobe carried out in a continuous manner by the use of, for example, apugmill. Optionally, after formation of the ice melting compositions,the compositions can be dried.

The components used in the presently disclosed methods are the same asthe components described above in connection with the ice meltingcompositions. For example, in one aspect, the coarse deicing particlenucleus used in the methods can comprise sodium chloride and have anucleus particle size within a range from about 500 μm to about 10,000μm. In certain aspects, the binder used in the methods can comprise amagnesium chloride brine or a sodium chloride brine with YPS. The YPScan be present, for example, in an amount ranging from about 2,000 ppmto about 5,000 ppm. The fine deicing particle coating can comprise orconsist of sodium chloride and comprise particles having particle sizeswithin a range from about 20 μm to about 600 μm. Again, the foregoingcomponents, amounts, and sizes are merely illustrative and anycomponent, amount, or particle size disclosed herein can be used inaccordance with the disclosed methods.

The amounts of each component of the ice melting composition addedduring the disclosed methods can also be the same as described above.For example, the methods recited herein can produce ice meltingcompositions having from about 60% to about 97% of the coarse deicingparticle nucleus, from about 0.5% to about 6% of the binder, and fromabout 3% to about 35% of the fine deicing particle coating. The methodsrecited herein can also produce ice melting compositions having about87% by weight of the coarse deicing particle nucleus, about 10% byweight of the fine deicing particle coating, and about 3% by weight ofthe binder. Again, the foregoing components, amounts, and sizes aremerely illustrative and any component, amount, or particle sizedisclosed herein can be used in accordance with the disclosed methods.

EXAMPLES Example 1

Certain experiments were carried out to determine the ice meltingcapabilities of various sized particles. In one experiment, ice wasmelted with compositions having a broad particle size distribution andwith compositions having a narrow particle size distribution. The broadparticle size distribution lot, shown as Composition 1 in FIG. 1,comprised sodium chloride particles having a particle size generallywithin the range of less than 600 μm to about 4750 μm. The narrowparticle size distribution lot, shown as Composition 2 in FIG. 1,comprised sodium chloride particles having a particle size less than 600μm.

Ice plates were prepared by pouring deionized water into disposable,polystyrene plates. The plates were stored in a room at a temperature of+5° F. The resulting ice plates were aged for about 48 hours prior touse. After the 48 hour time period, a known amount of the ice meltingcomposition was applied to the ice plates. Each ice plate was contactedwith only one aspect of the ice melting compositions. After the desiredamount of contact time had passed, the ice plate was tilted and anyexcess melt water was poured into an aluminum pan. The surface of theice plate was wiped with a dry paper towel to collect any remaining meltwater and undissolved ice melting composition. Additionally, the iceplate was removed from the tray and its underside was wiped with a drypaper towel to collect any water that may have collected there due topenetration of the ice by the ice melting composition.

The paper towels were placed in the aluminum pan and a second aluminumpan with holes punched in the side was placed on top and held in place.On completing the measurements, the pans were weighed, while ensuringthat there was no condensed moisture on them. The pans were then driedfor 16 hours at 80° C. and reweighed to give the amount of melt watercollected. Samples of the ice melting compositions were also dried underthe same conditions as the paper towels to determine the contribution,if any, of water in the ice melting compositions to the measured amountof melt water. The melt water measurement was corrected for the waterpresent in the amount of ice melting composition used.

The first experiment was carried out at +5° F. FIG. 1 indicates that theratio of the weight of melted water to the weight of the ice meltingcomposition was higher for Composition 2 than Composition 1 at all timeperiods. These results indicate that smaller sized particles will meltice faster than larger sized particles.

Example 2

In another experiment, particular aspects of the presently disclosed icemelting compositions were tested for ice melting capabilities. The sameexperimental steps described above were carried out where the icemelting compositions were added to ice plates at +5° F. For thisexperiment, five ice melting compositions were tested having thefollowing characteristics:

Composition 1: Coarse particle sodium chloride (particle size from about2300 μm to about 3400 μm);

Composition 2: Coarse particle sodium chloride nucleus (particle sizefrom about 2300 μm to about 3400 μm) coated with about 3% by weightsaturated NaCl brine containing about 4340 ppm YPS and about 10% byweight of fine particle sodium chloride (mean particle size of about 105μm);

Composition 3: Coarse particle sodium chloride nucleus (particle sizefrom about 2300 μm to about 3400 μm) coated with about 3% by weightsaturated NaCl brine containing about 4340 ppm YPS;

Composition 4: Coarse particle sodium chloride nucleus (particle sizefrom about 2300 μm to about 3400 μm) coated with calcium chloride brine(about 33% by weight) at about 10 gallons per ton (about 5.3% byweight); and

Composition 5: Coarse particle sodium chloride nucleus (particle sizefrom about 2300 μm to about 3400 μm) coated with magnesium chloridebrine (about 30% solution) at about 10 gallons per ton (about 5.1% byweight).

As can be seen in FIG. 2, Composition 2, which was coated with the fineparticle sodium chloride, outperformed all other ice meltingcompositions at all time periods analyzed.

Example 3

Another experiment was carried out to test the ice melting capabilitiesof certain aspects of the presently disclosed ice melting compositions.In this experiment, the procedures set forth in the previous experimentswere used and ice melting capabilities were measured over a 30 minutetime period at +5° F. The compositions used in this experiment were asfollows:

Composition 1: Coarse particle sodium chloride (particle size from about2300 μm to about 3400 μm);

Composition 2: Coarse particle sodium chloride nucleus (particle sizefrom about 2300 μm to about 3400 μm) coated with saturated magnesiumchloride brine at about 3% by weight and about 10% by weight of fineparticle sodium chloride (mean particle size about 105 μm); and

Composition 3: Coarse particle sodium chloride nucleus (particle sizefrom about 2300 μm to about 3400 μm) coated with about 3% by weightsaturated magnesium chloride brine.

The data obtained from this experiment, which is depicted in FIG. 3,indicates that the composition coated with the fine particle sodiumchloride outperformed the other compositions at all time periodsanalyzed.

All of the compositions and methods disclosed and claimed in thisapplication can be made and executed without undue experimentation inlight of the present disclosure. While this invention may be embodied inmany different forms, the foregoing provides specific embodiments of theinvention. The present disclosure is an exemplification of theprinciples of the invention and is not intended to limit the inventionto the particular embodiments illustrated. In addition, unless expresslystated to the contrary, use of the term “a” is intended to include “atleast one” or “one or more.” For example, “a composition” is intended toinclude “at least one composition” or “one or more compositions.”

Any ranges given either in absolute terms or in approximate terms areintended to encompass both, and any definitions used herein are intendedto be clarifying and not limiting. Notwithstanding that the numericalranges and parameters setting forth the broad scope of the invention areapproximations, the numerical values set forth in the specific examplesare reported as precisely as possible. Any numerical value, however,inherently contains certain errors necessarily resulting from thestandard deviation found in their respective testing measurements.Moreover, all ranges disclosed herein are to be understood to encompassany and all subranges (including all fractional and whole values)subsumed therein.

Furthermore, the invention encompasses any and all possible combinationsof some or all of the various embodiments described herein. It shouldalso be understood that various changes and modifications to thepresently preferred embodiments described herein will be apparent tothose skilled in the art. Such changes and modifications can be madewithout departing from the spirit and scope of the invention and withoutdiminishing its intended advantages. It is therefore intended that suchchanges and modifications be covered by the appended claims.

What is claimed is:
 1. An ice melting composition comprising: a coarsedeicing particle nucleus having a particle size range from about 500 μmto about 10,000 μm, a fine deicing particle coating substantiallysurrounding the coarse deicing particle nucleus, wherein the finedeicing particle coating consists of sodium chloride deicing particleshaving a particle size range from about 20 μm to about 600 μm and beingbonded to the coarse deicing particle nucleus with a binder.
 2. The icemelting composition of claim 1, wherein the coarse deicing particlenucleus comprises sodium chloride.
 3. The ice melting composition ofclaim 1, wherein the fine deicing particles have a particle size rangefrom about 100 μm to about 300 μm.
 4. The ice melting composition ofclaim 1, wherein the ice melting composition comprises from about 60% toabout 97% of the coarse deicing particle nucleus, from about 0.5% toabout 6% of the binder, and from about 3% to about 35% of the finedeicing particle coating.
 5. The ice melting composition of claim 1,wherein the binder is selected from the group consisting of a magnesiumchloride brine, a sodium chloride brine with yellow prussiate of soda, asolution containing inorganic salts, a solution of organic compounds, asolution of organic salts, an organic liquid, an inorganic salt solutioncontaining bio-derived organic materials, an organic solvent, and anycombination thereof.
 6. The ice melting composition of claim 5, whereinthe magnesium chloride brine is saturated and the sodium chloride brineis saturated.
 7. The ice melting composition of claim 5, wherein theorganic solvent is selected from the group consisting of glycerol,propylene glycol, and 1,3 propanediol.
 8. The ice melting composition ofclaim 5, wherein the sodium chloride brine with yellow prussiate of sodabinder comprises about 2,000 ppm to about 5,000 ppm of the yellowprussiate of soda.
 9. The ice melting composition of claim 1, whereinthe composition comprises from about 84% to about 90% of the coarsedeicing particle nucleus, from about 2% to about 4% of the binder, andfrom about 8% to about 12% of the fine deicing particle coating.
 10. Theice melting composition of claim 1, wherein the binder comprises amember selected from the group consisting of one or more dyes, one ormore corrosion inhibitors, and any combination thereof.